This invention relates to a work facilitating apparatus for conveying building material to a working place from a higher to a lower level near the place of use, particularly for conveying bricks for erection of inner walls such as the linings of converters, metallurgical furnaces, holding furnaces and the like.
U.S. Pat. No. 3,285,390 discloses a work facilitating apparatus for lining converters, which comprises a pair of endless conveyors one of which is a vertical paternoster elevator which is supported by a vertically suspended framework extending down through an opening at the upper end of the converter to a level near the bottom thereof. The suspended framework is supported by means of an upper frame resting on the upper end of the converter and carries, in addition to the vertical paternoster elevator, a working platform with means for receiving material from the paternoster elevator and conveying the material to the inner side of the converter. The other endless conveyor in the form of a conveyor belt is located outside the converter and extends obliquely upwardly from ground or floor level to the upper end of the vertical paternoster elevator for conveying material to the downwardly travelling run of the vertical conveyor which receives the material and conveys it down to the working platform.
This prior art apparatus suffers from several drawbacks.
One drawback resides in that the vertically suspended framework and the vertical paternoster elevator are of invariable length and that the working platform is vertically adjustable along the vertically suspended framework and the vertical paternoster elevator. When the vertically suspended framework and the vertical paternoster elevator are to be placed in and removed from the converter this must be done substantially in a vertical sense, which means that the available space above the upper end of the converter must be large enough to accommodate the entire length of the vertically suspended framework, or that the vertically suspended framework and the vertical paternoster elevator must be separable into sections, in which case the sections must be connected together above the converter when the vertical framework and its vertical paternoster elevator are suspended in the converter, or separated from one another when the vertical framework and its vertical paternoster elevator are to be removed from the converter.
Another drawback resides in that to permit being set at various working levels in the converter the working platform must be moved in relation to the vertical framework and in relation to the vertical paternoster elevator and be locked in each new position. In each working position the platform must be very securely locked to the vertically suspended framework to avoid the risk of the platform falling down, which might be a fall of up to 10 m or more. As the working platform must be set at its various height positions in relation to the vertically suspended framework, the vertical paternoster elevator has no definite material delivery end, that is the material is delivered on various levels along the vertical paternoster elevator depending upon the level at which the working platform is set. Irrespectively of the level at which the working platform is set between the lower and upper ends of the converter, the vertically suspended framework and the vertical paternoster elevator extend through the working platform down to a level at the bottom of the converter since the vertical framework and the vertical paternoster elevator are of invariable length. The means of the vertical paternoster elevator for conveying material must thus, after delivery of material to the working platform, continue their movements down to the lower end of the vertical paternoster elevator and from there up to the upper end of the elevator, which means that for a great part of the work done in the converter use is made of a vertical paternoster elevator which is of much too great a length in relation to the effective conveying distance.
A further serious drawback resides in that the outer endless conveyor by means of which the material is transferred to the vertical paternoster elevator delivers the material to entrainment means of the vertical paternoster elevator by dumping it from one to the other conveyor. This involves the great risk that material consisting of bricks weighing between 30 and 60 kg may fall down into the converter and hit the bottom of the converter or the working platform, breaking them into pieces or injuring the personnel on the working platform.
U.S. Pat. No. 4,033,463, describes a work facilitating apparatus in which use is made of an endless conveyor, one end portion of which forms a vertical conveyor part for conveying material inside the converter while the other end portion of the conveyor forms a horizontal or inclined conveyor part for substantially continuous conveyance of material. The conveyor according to this U.S. Patent thus forms a continuous conveying path the vertical path of which can be shortened by lengthening of the horizontal or inclined part, and vice versa. This will eliminate a risky material transfer from one conveyor to another.
The apparatus described in this U.S. Patent comprises a tubular supporting device which consists of telescopically extensible sections and which in a simple manner can be shortened and lengthened under simultaneous shortening and lengthening of the vertical part of the conveyor.